Windows NT 4.0 does’nt detect my HDD

WE have a IBM Netfinity 3500 server with SCSI HDD(2*4.3GB). Both the HDD’s are getting detected in the Boot process, but whenever I try to install Windows NT 4.0 it says there are no HDD present in ur Server. When installing Windows 9x or 2000 server I don’t find such problem……… It’s as easy as a piece of cake. So what might be the problem and solution for it?